Error 1: The key is incomplete / has gaps. There is no category for 10 chickens or 20 or 30 chickens.
Error 2: The key is missing a category for values over 39. The square with 42 chickens is not shaded, but there is no category for it in the key.
Error 3: The shading is inconsistent/incorrect. The square with 11 chickens (top middle) should be in the 11-19 category (light grey), but it is shaded dark grey (0-9). (Other shading errors exist, e.g., square with 25 should be medium grey but is light grey).
By comparing the data grid with the choropleth map, we can identify several errors:
1. **Gaps in the key:** The categories in the key are not continuous. For example, there is no group for a square with 10 chickens (between 9 and 11), or 20 chickens (between 19 and 21), or 30 chickens.
2. **Incomplete key:** The highest value in the data is 42, but the key only goes up to 39. There is no category for the square with 42 chickens, which explains why it is unshaded.
3. **Incorrect shading:** The shading applied does not consistently match the data and the key. For example:
- The top middle square has 11 chickens. According to the key, it should be light grey (11-19), but it has been shaded dark grey (0-9).
- The middle right square has 25 chickens. It should be medium grey (21-29), but it is shaded light grey (11-19).
- The bottom middle square has 34 chickens. It should be very light grey (31-39), but it is shaded medium grey (21-29).
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